Abstract： Objective： To reveal the feasibility of treating breast cancer based on syndrome differentiation of liver depression from the perspective of temperaments. Methods： The temperaments of 251 patients with breast cancer were collected through the Eysenck Personality Questionaire-Revised Short Scale For Chinese， and the meaning of the standard score of the four-dimension scale was analyzed to obtain the distribution of four temperaments. The correlation and connotation of each dimension scale were analyzed. Results： The standard scores of neuroticism， introversion/extroversion， lie detection and psychoticism of breast cancer patients were 41.73-62.07， 45.98-60.62， 48.49-58.55， 42.53-53.08， respectively. Patients with emotional instability accounted for 35.86%；extroversion accounted for 39.44%； high-honesty accounted for 79.68%， and psychoticism accounted for 8.77%. Patients with intermediate temperament accounted for 60.16%；patients with unstable introversion (melancholic) were more than the other three temperaments，and the stable extroversion (sanguine) accounted for the highest proportion of 54.17%. There was a strong positive correlation between emotional stability and personality (rs=0.704，P＜ 0.01). The proportion of breast cancer patients with unstable introversion as typical emotion (melancholic) was significantly larger than that of patients with introversion or extroversion (P＜0.01). Conclusion： The temperaments of breast cancer patients can be divided into two different types of liver depression caused by excessive liver qi or insufficient liver qi from the perspective of Chinese medicine.